This application claims priority of Taiwan Patent Application No. 091100112 filed on Jan. 7, 2002.
1. Field of Invention
The present invention relates to a cover structure and an image output apparatus including the cover structure.
2. Background of the Invention
The current trend of information presentation moves toward the multimedia approach, and image output apparatus is indispensable in this trend. There are many kinds of image output apparatus in the market, such as a projector, an overhead projector, and a slide projector. However, these apparatus all have similar problems of discharging of heat generated by the lamp within the apparatus.
Generally, a blowhole is provided in the apparatus to discharge the heat. However, light within the apparatus may leak from the blowhole to deteriorate the quality of output image. Therefore, the issue of leakage light should be considered while designing the blowhole. Conventionally, a plastic plate with multiple vents is deployed as a cover for the apparatus. Additionally, a fan may be arranged to cooperate with the plastic plate, such that the fan may discharge the airflow from the vents. On the plastic plate, a vane is arranged between locations of two vents to direct the discharged airflow to a desired direction. The other purpose of the vanes is to mask a portion of light, which leaks from the blowhole.
An advantage of this design is that the plastic cover may be made by mold method, and a length of the vanes may be such that they completely mask the light. However, the flow resistance encountered while discharging the airflow may increase due to the fact that the thickness of the plastic vane is large.
Another design for the cover is using a metal plate to substitute for the plastic plate. Multiple vanes and vents are formed by pressing the metal plate. The flow resistance encountered while discharging the airflow is reduced due to the thickness of the metal plate being smaller than plastic plate. However, the vanes of this type may not mask the leaking light completely. Therefore, a portion of light may leak from the cover and deteriorate the quality of the output image.
One aspect of the present invention is providing a cover structure disposed on an image output apparatus to discharge and to guide heated airflow within the image output apparatus.
Another aspect of the present invention is providing a cover structure to mask light leaking from a blowhole of the image output apparatus.
Another aspect of the present invention is providing a cover structure for reducing the resistance generated by discharging the heat air.
The present invention provides a cover structure disposed on the image output apparatus for discharging and guiding the heated airflow. The image output apparatus includes a housing and a lamp disposed within the housing. The housing further includes a blowhole. Additionally, the cover structure is provided to mask light emitting from the blowhole.
The cover structure includes a first device and a second device. The first device is disposed on the housing and corresponds to the blowhole to mask a portion of the light of the lamp emitting from the blowhole. The other portion of the light emitted from the lamp leaks from the first device to from a leakage light. The second device corresponds to an outer side of the first device to mask the leakage light.
The first device further includes at least one first vane and at least one first vent. And the second device includes at least one second vane and at least one second vent. In a preferred embodiment, the second vane may passage of the first vane such that the second vane may mask the leakage light leaking from the first device.
The present invention also provides an image output apparatus including the cover structure described above.
This and other aspects of the present invention will become clear to those of ordinary skill in the art after having read the following detailed description of the preferred embodiment which is illustrated in the various figures and drawings.